A. Field of the Invention
This invention relates generally to multi-user communication, and, more particularly, to a multimedia player implementing multi-user grouping nodes.
B. Description of the Related Art
The Moving Picture Experts Group (MPEG) is a working group of the International Organization for Standardization (ISO)that generates standards for digital audio and video compression. MPEG-1 and MPEG-2 are standards for interactive video on CD-ROM and Digital Television, respectively. MPEG-4 is a developing standard designed for efficient multimedia delivery and integration between a client and a server. MPEG-4 provides the flexibility to allow an end user to interact with multimedia content and to control the way that audiovisual objects are displayed. MPEG-4 is described more completely in the documents ISO/IEC JTC1/SC29/WG11, N1901, published Nov. 21, 1997, by the International Organization for Standardization (ISO) and ISO/IEC JTC1/SC29/WG11, N2323, published Jul. 1998, by the ISO.
MPEG-4 incorporates aspects of Virtual Reality Modeling Language (VRML), which describes three dimensional objects and worlds using a hierarchical scene graph (or scene description).1 Entities contained within the scene graph are called nodes. VRML 2.0 defines 54 different node types, including geometry primitives, appearance properties, sound properties, and various types of grouping nodes. Nodes store their data in fields, and VRML defines 20 different types of fields. Furthermore, nodes can contain other nodes and may be contained in more than one node. These nodes are processed by multimedia players using computer software to generate multimedia displays based on the scene graph.
1 The terms xe2x80x9cscene graphxe2x80x9d and xe2x80x9cscene descriptionxe2x80x9d are used interchangeably herein. VRML is described more fully in various texts, such as xe2x80x9cThe Annotated VRML 2.0 Reference Manual,xe2x80x9d by Rikk Carey and Gavin Bell, Addison-Wesley Developers Press (1997). 
Two of the node types defined in VRML 2.0 and MPEG-4 are the Group and the Group2D nodes. Both the Group and Group2D nodes are mechanisms by which one associates different media objects into a scene description. One limitation of VRML and MPEG-4 is that these Group and Group2D nodes are designed for a single end user, and therefore do not provide mechanisms for multi-user interaction. Multi-user interaction, however, is important for application domains such as collaborative computing, distance learning, shared virtual worlds, virtual chat, entertainment, and e-commerce, each of which involve interaction of two or more users with each other. There exists, therefore, a need for multimedia players providing multiple user interaction via a computer system.
Methods and apparatus consistent with the present invention, as embodied and broadly described herein, provide a multimedia player implementing multi-user communication via a computer system.
Consistent with the invention, a method for providing multi-user interaction in a computer system having multiple computers interconnected over a network includes receiving a multiuser group node by a first computer over the network, the multiuser group node having an owner other than the first computer, the first computer including a multimedia player presenting a multimedia display implemented by a scene graph, the node including a plurality of control parameters. The method further includes receiving an input request to access the node; accessing the node if a first control parameter is activated; and denying access to the node if the first control parameter is not activated
Consistent with the invention, an apparatus for providing multi-user communication includes at least one memory having program instructions, and at least one processor configured to use the program instructions. The processor executes the program instructions to perform the operations of receiving a multi-user group node in a multimedia player, the node including a plurality of control parameters; receiving an input request to access the node; accessing the node if a first control parameter is activated; and denying access to the node if the first control parameter is not activated.
Consistent with the invention, a computer-readable medium contains instructions for controlling a computer system to perform a method for providing multi-user communication. The method includes receiving a multi-user group node in a multimedia player, the node including a plurality of control parameters; receiving an input request to access the node; accessing the node if a first control parameter is activated; and denying access to the node if the first control parameter is not activated.